The present invention relates to a projecting and exposing apparatus, and more particularly, it relates to a projection-exposing apparatus capable of obtaining a large exposure area by composing an image pattern.
Recently, projection-exposing apparatuses have been indipensable to the manufacture of integrated semiconductor elements such as VLST. Further, it has been required for correctly projecting and exposing more detailed or minute patterns onto a wider area to obtain higher integrated articles.
However, in general, since ability of a projection lens incorporated into the projection-exposing apparatus is determined by a wave length of exposing light, numerical aperture (N.A.) of the lens and an area to be exposed, it is extremely difficult to treat a wide area, while shortening the wave length and maintaining the high N.A. in order to obtain an excellent resolving power. For this reason, it has been proposed to compose a picture or image by shifting a wafer, which is an object to be exposed, by a predetermined amount before each exposing operation, and repeating a plurality of exposing operations by means of a projection lens having a high resolving power only in a relatively narrow area, thereby treating a wider area while maintaining the high resolving power.
However, on composing the image, there arose a problem that a pattern formed in each exposing operation was not registered or aligned with a pattern obtained in the previous exposing operation in a boundary area thereof due to minuteness of the patterns derived from high integration, thereby causing an incorrect connection between the two adjacent patterns in the boundary area, with the result that circuit elements and the like did not present their normal characteristics.